Methods and devices for extracting thermal energy from the body core of a mammal

ABSTRACT

Methods and devices for extracting thermal energy from the core body of a mammal are provided. In practicing the subject methods, a portion of the mammal, e.g. a limb or portion thereof, is placed in a sealed enclosure to produce an enclosed portion of the mammal. A surface of the enclosed portion of the mammal is then contacted with a low temperature medium under negative pressure conditions for a period of time sufficient to provide for the desired core body thermal energy extraction. The subject methods and devices find use in a variety of applications, e.g. providing relief from temperature sensitive disorders, such as multiple sclerosis, and the treatment of hyperthermia, among other treatments. The subject methods and devices are particularly suited for use in enhancing the physical ability of a mammal.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] Pursuant to 35 U.S.C. §119(e), this application claims priorityto the filing date of the U.S. Provisional Patent Application Ser. No.60/199,016 filed Apr. 20, 2000 and U.S. Provisional Patent ApplicationSer. No. 60/199,015 filed Apr. 20, 2000; the disclosures of which areherein incorporated by reference.

INTRODUCTION

[0002] 1. Field of the Invention

[0003] The field of this invention is core body energy regulation.

[0004] 2. Background of the Invention

[0005] Instances exist where it is desired to extract thermal energy orheat from the body core of a mammal. For example, there are manyinstances in which it is desired to lower the internal body temperatureof a subject. Instances where it is desired to extract heat from thebody core of a subject include the treatment of hyperthermia, includingself-induced hyperthermia resulting from work or exercise, and thetreatment of temperature sensitive disorders, such as multiplesclerosis. For example, personal cooling systems are employed toalleviate symptoms of multiple sclerosis. In such methods, a patientwears a personal cooling system, e.g. a cooling helmet or garment, for acertain period of time during the day to alleviate symptoms.

[0006] While a number of different methodologies and devices have beendeveloped for use in reducing the core body temperature of a subject,there continues to be a need for the development of new devices andprotocols. Of particular interest would be the development of a deviceand protocol that provided for efficient heat extraction from the bodycore in a non-invasive manner that would be readily used by subjects,i.e. enjoy high patient compliance.

[0007] 3. Relevant Literature

[0008] U.S. Pat. No. 5,683,438. See also WO 98/40039. Also of interestare: Soreide et al., “A non-invasive means to effectively restorenonnothermia in cold stressed individuals: a preliminary report,” JEmerg. Med. (1999 July-August)17(4):725-30 and Grahn et al., “Recoveryfrom mild hypothermia can be accelerated by mechanically distendingblood vessels in the hand,” J. Appl Physiol. (1998) 85(5):1643-8. Seealso: Ku et al., Am. J. Phys. Med Rehabil. (September-October 1999)78:447-456; Ku et al., Am. J. Phys. Med. Rehabil. (November-December1996) 75:443-450; Capello et al., Ital. J. Neurol Sci. (1995) 16:533-539; Brown & Williams, Aviat. Space Environ Med. (1982) 53:583-586;Gordon et al., Med. Sci. Sports Exerc. (1990) 22:245-249; Watanuki, Ann.Physiol. Anthropol. (1993) 12:327-333; and Katsuura et al., Appl. HumanSci. (1996) 15:67-74. See also: Bruck K, Olschewski H. Body temperaturerelated factors diminishing the drive to exercise. Can J PhysiolPharmacol. 1987 June;65(6):1274-80; Schmidt V, Bruck K. Effect of aprecooling maneuver on body temperature and exercise performance. J ApplPhysiol. 1981 April;50(4):772-8; Hessemer V, Langusch D, Bruck L K,Bodeker R H, Breidenbach T. Effect of slightly lowered body temperatureson endurance performance in humans. J Appl Physiol. 1984December;57(6):1731-7; Olschewski H, Bruck K. Thermoregulatory,cardiovascular, and muscular factors related to exercise afterprecooling. J Appl Physiol. 1988 February;64(2):803-11; Booth J, MarinoF, Ward J J. Improved running performance in hot humid conditionsfollowing whole body precooling. Med Sci Sports Exerc. 1997July;29(7):943-9; Greenhaff P L, Clough P J. Predictors of sweat loss inman during prolonged exercise. Eur J Appl Physiol. 1989;58(4):348-52;Leweke F, Bruck K, Olschewski H. Temperature effects on ventilatoryrate, heart rate, and preferred pedal rate during cycle ergometry. JAppl Physiol. 1995 September;79(3):781-5; Lee D T, Haymes E M. Exerciseduration and thermoregulatory responses after whole body precooling. JAppl Physiol. 1995 December;79(6):1971-6; Marsh D, Sleivert G. Effect ofprecooling on high intensity cycling performance. Br J Sports Med. 1999December;33(6):393-7; and Gonzalez-Alonso J, Teller C, Andersen S L,Jensen F B, Hyldig T, Nielsen B. Influence of body temperature on thedevelopment of fatigue during prolonged exercise in the heat. J ApplPhysiol. 1999 March;86(3): 1032-9.

SUMMARY OF THE INVENTION

[0009] Methods and devices for extracting thermal energy from the bodycore of a mammal are provided. In practicing the subject methods, aportion of the mammal, e.g. a limb or portion thereof, is placed in asealed enclosure to produce an enclosed portion of the mammal. A surfaceof the enclosed portion of the mammal is then contacted with a lowtemperature medium under negative pressure conditions for a period oftime sufficient to extract the desired amount of heat from the body coreof the mammal. The subject methods and devices find use in a variety ofapplications, e.g. providing relief from temperature sensitivedisorders, such as multiple sclerosis, and the treatment ofhyperthermia.

[0010] The subject methods are particularly suited for use in enhancingthe physical ability of a mammal. In these embodiments, thermal energyis extracted from the core body of the mammal during the physicalprocedure for a period of time sufficient to enhance the ability of themammal to perform the physical procedure. To extract thermal energy fromthe core body of the mammal in the subject methods, a portion of themammal, e.g., a limb or portion thereof, is placed in a sealed enclosureto produce an enclosed portion of the mammal. A surface of the enclosedportion of the mammal is then contacted with a low temperature mediumunder negative pressure conditions for a period of time sufficient toprovide for the requisite core body thermal energy extraction. Thesubject methods and devices find use in the enhancement of the abilityof a mammal to perform a variety of different physical procedures,including athletic procedures.

BRIEF DESCRIPTION OF THE FIGURES

[0011]FIG. 1 provides a representation of a device according to thesubject invention.

[0012]FIG. 2 provides a graphical representation of the results from anassay demonstrating that core cooling can partially reverse musclefatigue of large dynamic muscles exercised to exhaustion.

[0013]FIG. 3 provides a graphical representation of the results from anassay demonstrating that core cooling restores power output of fatiguedlarge dynamic muscles.

[0014]FIG. 4 provides a graphical representation of the results from anassay demonstrating that regular exercise to exhaustion results in slowincrease in strength (conditioning).

[0015]FIG. 5 provides a graphical representation of the results from anassay demonstrating that repeated core cooling increases a subject'scapacity during individual conditioning episodes.

[0016]FIG. 6 provides a graphical representation of the results from anassay demonstrating that core cooling during conditioning enhancesstrength increases.

[0017]FIG. 7 provides a graphical representation of the results from anassay demonstrating that heat can be extracted from the core body of asubject using the device shown in FIG. 1.

[0018] FIGS. 8 to 13 provide various views of a device that can beemployed to practice to the subject methods.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

[0019] Methods and devices for extracting thermal energy from the bodycore of a mammal are provided. In practicing the subject methods, aportion of the mammal, e.g. a limb or portion thereof, is placed in asealed enclosure to produce an enclosed portion of the mammal. A surfaceof the enclosed portion of the mammal is then contacted with a lowtemperature medium under negative pressure conditions for a period oftime sufficient to extract the desired amount of heat from the body coreof the mammal. The subject methods and devices find use in a variety ofapplications, e.g. providing relief from temperature sensitivedisorders, such as multiple sclerosis, and the treatment ofhyperthermia.

[0020] The subject methods are particularly suited for use in enhancingthe physical ability of a mammal. In these embodiments, thermal energyis extracted from the core body of the mammal during the physicalprocedure for a period of time sufficient to enhance the ability of themammal to perform the physical procedure. To extract thermal energy fromthe core body of the mammal in the subject methods, a portion of themammal, e.g., a limb or portion thereof, is placed in a sealed enclosureto produce an enclosed portion of the mammal. A surface of the enclosedportion of the mammal is then contacted with a low temperature mediumunder negative pressure conditions for a period of time sufficient toprovide for the requisite core body thermal energy extraction. Thesubject methods and devices find use in the enhancement of the abilityof a mammal to perform a variety of different physical procedures,including athletic procedures.

[0021] In further describing the subject invention, the subject methodsand representative applications will be discussed in greater detail,followed by a review of representative devices for use in practicing thesubject methods.

[0022] Before the subject invention is described further, it is to beunderstood that the invention is not limited to the particularembodiments of the invention described below, as variations of theparticular embodiments may be made and still fall within the scope ofthe appended claims. It is also to be understood that the terminologyemployed is for the purpose of describing particular embodiments, and isnot intended to be limiting. Instead, the scope of the present inventionwill be established by the appended claims.

[0023] In this specification and the appended claims, the singular forms“a,” “an” and “the” include plural reference unless the context clearlydictates otherwise. Unless defined otherwise, all technical andscientific terms used herein have the same meaning as commonlyunderstood to one of ordinary skill in the art to which this inventionbelongs.

[0024] Methods

[0025] As summarized above, the subject invention provides methods forextracting heat or thermal energy from the body core of a mammal. Bycore body is meant the internal body region or portion of the mammal, asopposed to the surface of the mammal.

[0026] In certain embodiments, the subject invention provides methodsfor enhancing the ability of mammal to perform a physical procedure. Byenhancing is meant improving or bettering the ability of the mammal toperform a particular physical procedure, task or operation. In manyembodiments, this enhancement is distinct from a reduction in recoverytime of the mammal during a physical task or procedure, such that thesubject methods result in not a reduction in recovery time (althoughthis may be a manifestation) but also result in some additionalimprovement or enhancement. The nature of the enhancement may varydepending on the specific nature of the physical task. For example,where the physical procedure or task is an athletic procedure, e.g.participation in a game, a training or exercise routine, a long distancerun or swim, etc., the enhancement is generally in the form of animprovement in the athletic ability of the mammal to perform theathletic procedure, e.g. by increasing the length of time a participantcan play in a game (at peak performance), increasing workout capacity,improving the training program (e.g. by increasing the time anindividual can train, increasing the number of weight repetitions thatcan be done, improving a training regimen, etc.) so that an individualcan perform a particular task, e.g. race, better, etc. Likewise, wherethe physical procedure or task is a work or employment related procedureor task, the enhancement may be in the form of increased output from thework or related procedure over a given period of time. Further examplesof different types of enhancements that may be accomplished with thesubject methods are provided below in connection with the representativephysical procedures in which the subject methods may be employed. Ingeneral, the amount of enhancement in ability observed in practicing thesubject methods, as compared to a control, is at least about 1.2 fold,usually at least about 1.5 fold and more usually at least about 2.0fold, where the amount of enhancement may be as high as 6.0 fold orhigher.

[0027] In practicing the subject methods, thermal energy is extractedfrom the body core of the mammal at least once during the physicalactivity to result in the desired ability enhancement. By body core ismeant the internal region of the mammal, as opposed to the surface ofthe mammal. The magnitude of core body thermal energy extractionaccomplished during practice of the methods may vary, and is sufficientto provide for the desired outcome, e.g. reduction in core bodytemperature, ability enhancement, relief from hyperthermia, MS symptoms,etc,. and the like. In many embodiments, the magnitude of heatextraction is generally at least about 0.5 Kcal/min, usually at leastabout 1.0 Kcal/min and more usually at least about 1.5 Kcal/min, wherethe magnitude may be as great as 50 Kcal/min or greater, but generallydoes not exceed about 30 Kcal/min and usually does not exceed about 20Kcal/min. The period of time that the heat is extracted from the corebody may vary, but typically ranges from about 1 min to 24 hrs, usuallyfrom about 2 min to 20 min and more usually from about 2 min to 5 min.

[0028] In certain embodiments, the core body temperature of the subjectis reduced. The magnitude of core body temperature reduction issufficient to provide for the ability enhancement, and is generally atleast about 0.5, usually at least about 1.0 and more usually at leastabout 1.5° C., where the magnitude may be as great as 4° C. or greater,but generally does not exceed about 4.0° C. and usually does not exceedabout 2.0° C. The period of time that the core body temperature isreduced may vary, but typically ranges from about 1 min to continuousfor duration of activity, usually from about 2 to 20 min and moreusually from about 2 to 5 min. In other embodiments, the subject methodswill prevent or minimize rises in the core body temperature.Nonetheless, in these embodiments the subject methods do extract heat orthermal energy from the core body of the subject, but the amount ofenergy being produced by or introduced into the core body of the subjectfrom other sources is substantially the same as or exceeds the amount ofenergy being extracted from the core body by the subject methods.

[0029] Where the specific embodiment is a method of enhancing physicalability, the heat or thermal energy is extracted from the core body atleast once during the physical procedure, where the procedure is measurefrom a point prior to the beginning of the procedure to the end of theprocedure, e.g., to the end of a training set, to the end of a game, tothe end of given work day, etc. In certain embodiments, core body heatis extracted a plurality of times. Where core body heat is extracted aplurality of times, the number of different times that heat is extractedtypically ranges from about 2 to 20, usually from about 2 to 15 and moreusually from about 5 to 10. In certain embodiments, core body thermalenergy is extracted a single time. The term procedure is used broadly toinclude anything from a single physical movement to a plurality ofphysical movements that are practiced in a given period of time, e.g.participation in a game, performing a particular training regimen,activity encountered during an entire workday etc.

[0030] In extracting core body thermal energy from the mammal, a surfaceof the mammal is contacted with a low temperature medium under negativepressure conditions for a period of time sufficient to achieve thedesired reduction in core body temperature. The surface that iscontacted with the low temperature medium is generally a heat exchangesurface that acts as a heat exchange means between the core body and theenvironment of the mammal. Heat exchange surfaces of interest with thesubject methods include those found in various regions of the mammal,e.g. the arms, legs, palms, soles, head, face, ears, and the like.

[0031] By negative pressure conditions is meant a pressure lower thanambient pressure under the particular conditions in which the method isperformed, e.g. 1 ATM at sea level. The magnitude of the decrease inpressure from the ambient pressure under the negative pressureconditions is generally at least about 20 mmHg, usually at least about30 mmHg and more usually at least about 35 mmHg, where the magnitude ofthe decrease may be as great as 85 mmHg or greater, but typically doesnot exceed about 60 mmHg and usually does not exceed about 50 mmHg. Whenthe method is performed at or about sea level, the pressure under thenegative pressure conditions generally ranges from about 740 to 675,usually from about 730 to 700 and more usually from about 725 to 710mmHg.

[0032] As mentioned above, the surface of the mammal is contacted with alow temperature medium under the negative pressure conditions. By lowtemperature medium is meant a medium that has a temperature that issufficient to provide the requisite core body thermal energy or heatextraction or removal. The nature of the medium may vary, the mediumbeing a temperature controlled solid material, e.g. cooling blanket, aliquid, or gas, depending on the particular device employed to practicethe subject methods. The temperature of the low temperature medium mayvary, but generally is not so low as to cause local vasoconstriction atthe surface of the mammal, e.g. the heat exchange surface. The lowtemperature medium generally has a temperature ranging from about 0 to35, usually from about 10 to 30 and more usually from about 15 to 25° C.In many embodiments, a feature of the subject methods is that thetemperature of the low temperature medium is specifically selected to beone that provides for thermal energy extraction from the core body andnot local vasoconstriction.

[0033] Contact is maintained for a period of time sufficient for thedesired amount of core body thermal energy extraction to occur. As such,contact is generally maintained for at least about 1 min, usually atleast about 2 min and more usually at least about 3 min, where contactmay be maintained for up to 10 hr or longer, but is generally notmaintained for longer than 1 hour and usually is not maintained forlonger than 5 min.

[0034] In practicing the subject methods, the negative pressureconditions during contact may be static/constant or variable. Thus, incertain embodiments, the negative pressure is maintained at a constantvalue during contact of the surface with the low temperature medium. Inyet other embodiments, the negative pressure value is varied duringcontact, e.g. oscillated. Where the negative pressure is varied oroscillated, the magnitude of the pressure change during a given periodmay be varied may range from about −85 to 40 mmHg, usually from about−40 to 0 mmHg, with the periodicity of the oscillation ranging fromabout 0.25 sec to 10 min, usually from about 1 sec to 10 sec.

[0035] In practicing the subject methods, the negative pressureconditions may be provided using any convenient protocol. In manyembodiments, the negative pressure conditions are provided by enclosinga portion of the mammal that includes the target surface that is to becontacted with the low temperature medium in a sealed enclosure, wherethe pressure is then reduced in the sealed enclosure thereby providingthe requisite negative pressure conditions. The portion that is enclosedin the sealed enclosure is a portion of the mammal that includes thetarget heat exchange surface, and therefore is an appendage in manyembodiments of the subject invention. As such, the portion that issealed is an arm or leg, or at least a portion thereof, e.g. hand orfoot, in many embodiments of the subject invention. The nature of theenclosure will vary depending on the nature of the appendage to beenclosed, where representative enclosures include gloves, shoes/boots,or sleeves, where the latter is described in greater detail supra inconnection with the description of the representative devices that canbe used to practice the subject invention.

[0036] In certain embodiments, the subject methods may further include afeedback means that at least partially controls when the heat exchangesurface of the mammal is contacted with the low temperature medium toextract thermal energy from the core body of the mammal. The feedbackmeans may be any convenient means, where a suitable means is athermosensor, e.g. placed over a heat exchange surface not beingcontacted with the low temperature medium. In such embodiments, themethod generally further includes a data processing step for processingthe feedback data and activating the contact with the low temperaturemedium in response thereto, e.g. a computing means that controls thecontact of the heat exchange surface with the low temperature medium.

[0037] The subject methods are suitable or use with a variety ofmammals. Mammals of interest include, but are not limited to: raceanimals, e.g. horses, dogs, etc., work animals, e.g. horses, oxen etc.,and humans. In most embodiments, the mammals on which the subjectmethods are practiced are humans.

[0038] Utility

[0039] As demonstrated above, the subject methods provide a means forextracting thermal energy or heat from the core body of a mammal. Assuch, the subject methods are suitable for use in a variety of differentapplications, where representative applications include the treatment ofnormal and abnormal physiological conditions, e.g. disease, where corebody heat extraction is desirable. Representative applications in whichthe subject methods find use include the treatment of exercise or workinduced hyperthermia, treatment of stroke, treatment of cystic fibrosissymptoms, treatment of multiple sclerosis symptoms, and the like. Bytreatment is meant at least an alleviation in one or more of thesymptoms associated with the condition being treated, e.g. a reductionin discomfort, amelioration or elimination of symptoms, etc.

[0040] In many embodiments, the subject methods are employed forenhancing the ability of a mammal to perform a physical procedure ortask. As such, the subject methods are suitable for use in a variety ofdifferent applications where a variety of different types of physicalprocedures are performed. For illustration purposes only, the followingrepresentative applications are provided. However, it should be notedthat the subject methods are suitable for use in the enhancement of thephysical ability of a mammal to perform a plethora of other physicalprocedures not described below.

[0041] One type of physical ability that may be enhanced by practicingthe subject methods is athletic ability. In other words, the methods maybe used to improve the ability of a mammal to perform an athleticprocedure. The nature of the improvement or enhancement may vary greatlydepending on the nature of the athletic procedure being practiced by themammal. Representative enhancements include, but are not limited to:increases in strength, e.g. as measured by ability to lift a particularweight, etc.; increases in stamina, e.g. as measured in terms of abilityto perform a task or play a sport without resting, etc.; increases inthe ability of the mammal to perform repetitions of a physical task,e.g. weight lifts, pull ups, etc; and the like. As mentioned above, themagnitude of the enhancement is generally at least about 1.2 fold,usually at least about 1.5 fold and more usually at least about 2.0fold, where the magnitude of the enhancement may be as high as 6.0 foldor higher.

[0042] Another type of physical ability that may be enhanced bypracticing the subject methods is physical work ability. In other words,the subject methods may be used to improve the ability of mammal toperform a particular work related physical procedure. Examples of workrelated physical procedures include, but are not limited to: physicalbuilding and maintenance of equipment, particularly in hot environments;agricultural labor, e.g. crop harvesting; moving office and homefurnishings; building and construction, e.g. of homes and offices; civicstructure building and maintenance, etc. Enhancement may take many formsincluding, but not limited to: increasing the number of repetitivemovements that may be performed; increasing the length of time aparticular job may be performed without resting; reducing errors in aparticular job; etc. Again, the magnitude of the enhancement isgenerally at least about 1.2 fold, usually at least about 1.5 fold andmore usually at least about 2.0 fold, where the magnitude of theenhancement may be as high as 6.0 fold or higher.

[0043] In many embodiments, the subject methods result in more than areduction in recovery time to provide some other enhancement orimprovement, as exemplified above, e.g., enhanced physical ability,increase workout capacity, etc.

[0044] As mentioned above, the above athletic and work related physicalprocedures are merely representative of the procedures that may beenhanced using the subject methods.

[0045] Devices

[0046] The above described methods may be practiced using any convenientdevice. In general, any device that is capable of achieving negativepressure and low temperature medium contact with the target heatexchange surface for the requisite period of time may be employed. Ingeneral, devices employed in the subject methods include a means forproviding the negative pressure environment at the target heat exchangesurface and means for contacting the heat exchange surface with the lowtemperature medium. In many embodiments, the subject devices include ameans for sealing an appendage of the mammal in an enclosed environmentin which negative pressure conditions can be produced. Representativeenclosing means include sleeves, boots/shoes, gloves, etc.Representative means for contacting the surface with a cooling mediuminclude: cooling blankets, cold water immersion means, cooling gasmeans, etc.

[0047] A representative device for use in practicing the subject methodsis provided in FIG. 1. As shown in FIG. 1, core body cooling apparatus10 includes an enclosing element 12 in the form of a hollow, tubular,elongated sleeve. Sleeve 12 is dimensioned to fit around a body portion62, preferably an appendage, e.g. arm. In the embodiment illustrated inFIG. 1 appendage 62 is an arm.

[0048] Sleeve 12 can be made of virtually any non-hazardous materialwhich retains the requisite shape while the interior of sleeve 12 ismaintained at negative pressures. In particular, sleeve 12 has tosupport negative pressures down to at least −85 mmHg. In a preferredembodiment, sleeve 12 is made of pliant and elastic materials which caninclude supporting or reinforcing members. This type of constructioneasily accommodates movements of arm 62 and thus provides the mammalwith more comfort and freedom during practice of the subject methods. Inthe present embodiment sleeve 12 is a neoprene-impregnated polyestersheath supported on a spring steel wire helix.

[0049] Sleeve 12, as shown in FIG. 1, has a distal end or rim 14 and aproximal end or rim 16. Distal rim 14 is capped by a sealing element 60capable of creating an airtight seal. In this embodiment element 60 is aplastic plate. However, a cap or other sealing element can be used withequal success. In certain embodiments, sleeve 12 may be closed off atdistal end 14.

[0050] A flexible flange 20 is attached to proximal rim 16. Flange 20 ispreferably made of a synthetic material impermeable to air. The tubularform of flange 20 ensures that it fits snugly around arm 62 and conformsto the arm's shape. In the present embodiment 20 is made of Neoprene(R).

[0051] Elongated sleeve 12 is provided with a pressure inlet 22. Apressure conduit 24, e.g., a flexible tube, is connected to inlet 22.The other end of conduit 24 is connected to a vacuum pump 26. Vacuumpump 26 is a standard pump capable of generating negative pressures downto −85 mmHg and beyond inside sleeve 12. The delivery of this negativepressure through conduit 24 can be regulated by any conventionalmechanisms. In the embodiment shown, an adjustable valve 28 guaranteesmaintenance of the desired pressure inside sleeve 12. Conveniently, areadout gauge 32 is also provided for visual pressure indication.

[0052] A cooling element 34 is lodged inside elongated sleeve 12. In thepreferred embodiment, cooling element or medium 34 is a cooling blanketfilled with a cooling fluid 30. Because of its high heat capacity andgeneral safety, water is particularly well-suited for cooling fluid 30.Cooling blanket 34 extends along the length of sleeve 12 and wrapsaround arm 62. In certain embodiments, it is desirable that the area ofcontact between arm 62 and blanket 34 be as large as possible.

[0053] Blanket 34 is connected to a fluid inlet 40 and a fluid outlet56. A supply conduit 42 and a return conduit 58, both preferably made ofa flexible tubing, are attached at inlet 40 and outlet 56 respectively.At their other ends conduits 42 and 58 are connected to a cooling andcirculating system 44. Preferably, system 44 is a fluid cooler and acirculating pump (not shown). Suitable fluid coolers (e.g. refrigerationmeans) and pumps are commercially available and commonly known. Inaddition, system 44 has a control indicator 46 for indicating thetemperature of fluid 30 and its rate of flow.

[0054] Core body cooling apparatus 10 is simple to use. First, themammals arm 62 is placed inside sleeve 12 such that cooling blanket 34envelops arm 62 and remains in contact with it. In this position, flange20 wraps around the upper portion of arm 62. To ensure that flange 20conforms closely to the contour of the upper portion of arm 62 thelatter is preferably bare.

[0055] With arm 62 properly inserted into sleeve 12, pump 26 isactivated to produce a negative pressure between −20 mmHg and −85 mmHginside sleeve 12. Under the influence of negative pressure or suction,flange 20 seals tightly around the upper part of arm 62 to preserve thevacuum inside sleeve 12. At the same time, cooling and circulatingsystem 44 is also activated to cool and pump cooling fluid 30 throughcooling blanket 34. In particular, cooling fluid 30 is delivered throughsupply conduit 42 and recirculated through return conduit 58. Controlindicator 46 is used for setting the proper flow rate and temperature offluid 30.

[0056] The device shown in FIG. 1 and described below is merelyrepresentative of devices that can be employed to practice the subjectinvention. Other device configurations are possible, e.g. ones in whichthe sleeve is replaced with a glove, shoe/boot, etc, and come within thescope of the subject invention.

[0057] FIGS. 8 to 13 provide various view of another embodiment of adevice that can be employed to practice the subject invention. Thefeatures of the system depicted in FIGS. 8 to 13, belonging to AVACoreTechnologies, Inc. (Palo Alto, Calif.), are preferred for carrying outthe methodologies described herein. The system described includes anegative pressure chamber in which to apply or remove thermal energyfrom a human subject. An improved interface between the chamber and itsexternal environment is provided.

[0058] Aquarius, Inc. (Scottsdale, Ariz.) produces a system that may beused or variously modified for use in the stated method(s). However,that system utilizes a “hard” seal interface with a user. The systemdescribed herein may utilize a “soft” seal. A “hard” seal ischaracterized as one designed to altogether avoid air leakage past theboundary it provides. In theory, a “hard” seal will allow a singleevacuation of the negative pressure chamber for use in the methods. Inpractice, however, a “hard” seal can produce a tourniquet effect. Also,any inability to maintain a complete seal will be problematic in asystem requiring as much.

[0059] A “soft” seal as described herein is characterized as providingan approximate or imperfect seal at a user/seal interface. Such a sealmay be more compliant in its interface with a user. Indeed, in responseto user movement, such a seal may leak or pass some air at the user/sealinterface. In a negative-pressure system designed for use with a softseal, a regulator or another feedback mechanism/routine will cause avacuum pump, generator, fan or any such other mechanism capable ofdrawing a vacuum to respond and evacuate such air as necessary tostabilize the pressure within the chamber, returning it to the desiredlevel. Active control of vacuum pressure in real-time or atpredetermined intervals in conjunction with a “soft” seal provides asignificant advantage over a “hard” seal system that relies on simplypulling a vacuum with the hopes of maintaining the same.

[0060] A further disadvantage over the Aquarius system has more to dowith seal configuration than its barrier function. Entry and exit fromthe Aquarius seal is difficult. Whether “hard” or “soft” in function,the present system provides a two-sided seal configuration. The meaningof this will be more apparent in view of the following figures anddescriptive text.

[0061]FIGS. 8 and 9 provide fore and aft perspective views of a negativepressure thermal exchange module (100). FIG. 10 provides an explodedview of the same. The system components not shown in the figures includea thermal control or perfusion unit. Such a unit may be adapted toprovide a stream of heat exchange media such as water at elevatedtemperatures, lowered temperatures or both. Further, a vacuum source andregulator optionally used with module (100) are not shown. Any sort ofvacuum source or regulator/control mechanism may be used with module(100) as would be apparent to one with skill in the art. Together, thesecomponents work to maintain a pressure within module (100) during usebetween about 20 and 25 inches of H₂O and temperatures for core bodycooling between about 19 and 22° C. or temperatures for core bodyheating between about 40 and 45° C.

[0062] As shown, module (100) includes a housing (102) defining anegative pressure chamber (104), a heat-exchange element (106) and asoft, two-sided seal (108) supported by seal frame elements (110).

[0063] Housing (102) may be made from a cover (112) and a base (114).Negative pressure chamber (104) is preferably provided between heatexchange element (106) and cover (112). The embodiment shown is adaptedto fit the hand of a human user. Chamber (104) is preferably configuredto fit a human hand of any size. In order to provide a morespace-efficient package, however, it may be more preferably sized to fit95% of human hand sizes. Alternately, it may be sized for moreparticularized groups, such as children. It is also contemplated thatthe housing may be configured to fit a human foot since the undersurface of a foot may also be used effectively as a heat exchangesurface.

[0064] Housing (102) may be constructed from multiple pieces, includingan end cap (116) as shown, or it may be provided as a unitary structure.Cap (116) is shown including a ports (118). A first port may be utilizedfor connection to a vacuum source, while the second may be utilized fora vacuum gauge. Of course, alternate port placement is also possible.

[0065] Preferably, housing (102) is made of plastic. Most preferably,the material and design of at least a portion of module (100) are suchthat housing (102) may be produced by vacuum forming or moldingtechniques.

[0066] Where discrete cover (112) and base (114) portions are used, theymay be mechanically secured to one another through bolt holes (120). Insuch an instance, a gasket or caulking may be employed to seal theperiphery of housing (102).

[0067] Providing a separable cover (112) and base (114) or heat exchangeelement (106) provide advantageous access to clean module (100) afteruse. However, it is contemplated that the top and bottom portions of themodule may be fused together, for instance, by ultrasonic welding,chemical bonding or otherwise. Also, as noted above, it is contemplatedthat housing (102) may be provided in a single piece.

[0068] Regardless of the construction, sizing or overall appearance ofhousing (102), it defines a portion of chamber (104). A heat exchangesurface (122) for delivering or accepting a thermal load from a useralso defines a portion of chamber (104). A user may directly contactheat exchange surface (122). Alternately, a user may wear a glove orsock or take other prophylactic measures. Heat exchange surface (122)may be provided by a member separate from heat exchange member (106)such as by an intermediate layer of foil, metalized Mylar or anothermaterial.

[0069] Heat exchange element (106) is preferably made of aluminum oranother high thermally-conductive material. It may be in communicationwith a Peltier device, a desiccant cooling device or an endothermic orexothermic chemical reaction to provide a temperature variance. Morepreferably, however, heat exchange member (106) is in communication withat an inlet and an outlet (124) to accommodate a flow of perfusionliquid behind heat exchange surface (122). Chilled or heated water maybe used to maintain the contact surface of the element at a desiredtemperature. Optimally, perfusion fluid is run through a series ofswitchbacks in cavity (126) between element (106) and base (114).

[0070] A rear portion of housing (102) and heat exchange member (106)may be provided by plate (128). As depicted, this portion may includeprovision for inlet and outlet (124) to heat exchange cavity (126) andan opening (130) to chamber (104). A preferred manner of constructingseal (108) is disclosed in connection with plate (128).

[0071] Views detailing preferred geometric aspects of seal (108) areshown in FIGS. 11, 12 and 13. FIG. 11 shows an end-on view of seal(108). Preferably, at least portions of seal (108) are ovalized in form.An elliptical shape may be preferred. A circular shape may also be used.Still, a shape having a major axis (132) and a minor axis (134) will bepreferred, at least for the waist opening (136) of seal (108). Anovalized shape approximately corresponds to the shape of the wrist orforearm of a user. A shape having a major axis (132) and a minor axis(134) will also be preferred at chamber opening (130) and seal opening(138). This will assist in providing clearance for hand entry and exitof module (100). It will also simplify the construction of seal webbing(140).

[0072] Whether or not ovalized features are utilized for seal (108), itwill be shaped roughly like an hourglass. Seal (108) will most closelyresemble an hourglass if openings (130), (136) and (138) are circular.When ovalization is applied, different projected views of seal(108)—such as viewed in FIG. 12, for the section taken along line A-Aand in FIG. 6 for the section taken along line B-B—display an hourglassshape.

[0073] Of course, the shapes depicted may be characterized as other than“hourglass” forms. For instance, profiles of seal (108) may be viewed ashyperbolic or parabolic. Further, simple radiused or semi-circularcross-sections may be utilized in producing seal (108). Furtherstraightened sections may be used, especially, between the openings(130) and (138) and waist (136).

[0074] Whatever the case, a two-sided seal with outside openings of agreater size than that of the inside opening is to be used in module(100). This geometry provides for ramps or transition sections forappendage entry and exit. These features assist in stretching the sealinterface or waist (136) sufficiently wide to pass a hand or foot bothfor insertion into and removal from module (100).

[0075] Material selection is important in providing such a seal.Clearly, the material must be able to stretch. Further, it shouldprovide a substantial barrier to air flow. To meet each of thesecriteria, a urethane-backed lycra available from Malden Mills (Malden,Mass.) has proven effective. Still, it is contemplated that othermaterials may be used. The material (or materials) selected for webbing(140) preferably has a finish that does not grip onto a user so as tocomplicate entry and exit from module (100). The urethane skin of thereferenced material has a satin finish. This decreases friction with theskin and hair of a user.

[0076] In addition to providing sufficient stretch, the seal webbingmaterial should also have sufficient strength to avoid being drawn toofar into cavity (104) upon the application of vacuum. When in use, theopen construction of seal (108) will result in cavity-side webbingmaterial exposed to partial vacuum within chamber (104) to be forced byambient pressure inward. This self-inflation phenomena observed for thechamber-side of the seal may be of assistance in providing seal patencywith a user. However, if too much material bows inward, it will resultin an uncomfortable or disconcerting displacement of the user's hand orfoot into the device. Accordingly, with proper material choice, the sideof seal (108) opposite chamber (104) provides not only a transitionsection for entry and exit, but also a stabilizing feature for sealposition.

[0077] Seal (108) is preferably formed by a sleeve made by stitching twopieces of webbing material (140) together where they are shown brokenapart in the exploded view of FIG. 10. By constructing the sleeve fromtwo or more pieces, complex shapes can be easily produced. To secure thesleeve webbing (140) in place to form seal (108), it is folded overrings (142) at each end as variously depicted. Then the cavity-side ringand webbing is captured in opening (130) of plate (128). The oppositeside of seal webbing (140) is captured between outer ring (142) andretainer member (144). Standoffs (146) or equivalent structure spaceplate (128) and ring retainer (144) apart to define the overall lengthof seal (108). Of course, the length of the standoffs or seal may bevaried as well as the other parameters of seal (108) that effect fit.

[0078] In this respect, it is noted that it may be desirable to providea longer overall seal in some instances. Increasing overall lengthprovides further design flexibility with seal shape. This may be besttaken advantage of by increasing the length of waist (134) to providegreater seal surface contact with a user. This may beneficially reduceany undesirable constricting effects. Furthermore, it is to beappreciated that the nature of the material used for the seal webbing(140) may be advantageously varied. While the noted lycra-based materialis isotropic in nature, an anisotropic material or effect may bepreferred for the webbing. This is to say that greater radial expansionof the sleeve may be desirable, whereas longitudinal compliance may notbe. By reducing compliance along the axis of the sleeve relative to aradial component, it will tend to be drawn into chamber (104) to alesser degree upon the application of vacuum. For a very high-stretchmaterial, this will allow for smaller seal openings to fit the samepopulation (since they can still stretch webbing (140) radially and haveit return sufficiently to form a desired seal), without forfeiting thefull set of advantages that the two-sided seal described offers.

[0079] Such an anisotropic effect may be achieved in a number of ways.It may be accomplished by providing longitudinal reinforcement member(s)associated with the webbing. They may be incorporated through braidingtechniques, by bonding/affixing stiffener(s) to the sleeve surface or byother means as would be apparent to one with skill in the art.

[0080] Regardless of the particulars of seal construction and whether itis utilized to provide a “hard” or “soft” user interface, the dual-sidedseal disclosed provides a superior manner of carrying out themethodology noted above. Though a “soft” two-sided seal as shown in thefigures is preferred for its elegance in approach and proveneffectiveness, a “hard” or more complex “soft” seal approach mightsometimes be desired.

[0081] In order to utilize the dual-sided seal in a “hard” approach,supplemental forcing means may be provided to apply pressure around sealwaist (134). Mechanical means such as at least one of a strap, belt orcinch may be used. Alternately an inflatable cuff or bladder portionsaround the periphery of the seal may be employed. While the systemcomplexity will increase due to provision for providing the supplementalpressure and controlling it by either automated or manual means, certainpotential advantages arise. It may enable a single-evacuation procedurefor chamber (104) rather than relying on constant or periodic vacuumreplenishment. It may also provide greater design flexibility for seal(108). Particularly, by providing another variable to utilize in designdecisions, a lesser emphasis may be placed on webbing material choice oropening sizing since the supplemental forcing capacity may be used toshape the seal as desired in use. Further, it may enable fitting seal(108) to a wider range of a populous for a given configuration of hardelements, such as those that make-up seal frame (110).

[0082] Supplemental forcing or seal shaping means may also be used toproduce a more complex “soft” seal than that described above. As with a“hard” seal approach, this would open design and fit possibilities.Forcing or seal shaping parameters may, again, be controlled manually orautomatically. Except, in a complex “soft” seal, the control of pressureapplied to waist (134) is gauged to provide a compliant feel or fit.Since the application of pressure on the seal interface with the usermay be the only difference between a complex “soft” seal approach and a“hard” seal approach utilizing the dual-sided configuration, the sameapparatus may be configured to function in either manner, for instance,by providing variable pressure control.

[0083] The following examples are offered by way of illustration and notby way of limitation.

Experimental

[0084] I. Pull Up Test

[0085] A. Introduction

[0086] Pull-ups were used as exercise regime to increase metabolic heatproduction and produce hyperthermia.

[0087] Subject is a 33

[0088] year old male who maintained a regular regime of strengthconditioning prior to this study.

[0089] Trials were run 2 to 3 times per week

[0090] Each trial consisted of sets pull-ups performed to exhaustion at3.5 minute intervals. Tympanic membrane temperature was recordedcontinuously

[0091] B. Methods

[0092] Core cooling is achieved by placing hand and forearm undernegative pressure and cooling skin with water perfused pad.

[0093] Subject places hand and forearm in sealed chamber shown in FIG.1.

[0094] Air is withdrawn from chamber to create subatmospheric pressure.

[0095] Cool water (17 to 20° C.) is pumped through pad surrounding handand forearm

[0096] Process takes two to three minutes and can extract excess heatproduced by large dynamic muscle exercise.

[0097] Heat extraction is calculated from water perfusion rate and thedifference between inlet and outlet temperatures. See FIG. 7.

[0098] Sweating is reduced.

[0099] C. Core cooling can partially reverse muscle fatigue of largedynamic muscles exercised to exhaustion

[0100] Subject completes as many pull-ups as possible in individual setsspaced 3.5 minutes apart.

[0101] Capacity for power output declines with repeated sets ofpull-ups.

[0102] One three minute core cooling returns power output to initialvalue.

[0103] A subsequent two-minute core cooling also increases subsequentpower output.

[0104] The results are graphically illustrated in FIG. 2.

[0105] D. Core cooling restores power output of fatigued large dynamicmuscles

[0106] Subject was asked to do pull-ups to exhaustion every 3.5 minutesfor 45 minutes.

[0107] First set of pull-ups averaged 14

[0108] Ninth set of pull-ups averaged 8

[0109] Following 3 minutes of core cooling the tenth set of pull-upsaveraged 13.

[0110] In control runs the tenth set of pull-ups averaged 10.

[0111] Thus, power output following core cooling was increased 60% overpretreatment and 33% over control

[0112] The results are graphically illustrated in FIG. 3.

[0113] E. Regular exercise to exhaustion results in slow increase instrength (conditioning)

[0114] Subject did pull-ups to exhaustion in sets spaced 3.5 minutesapart for 45 minutes about twice weekly

[0115] Over 6 weeks the capacity of the subject for pull-ups increasedby less than 2 fold.

[0116] The results are graphically illustrated in FIG. 4.

[0117] F. Repeated core cooling increases subject's capacity duringindividual conditioning episodes

[0118] Subject was requested to do pull-ups to exhaustion at 3.5 minuteintervals.

[0119] Without core cooling the subject's capacity steadily declinedfrom an initial 20 to a final 9 pull-ups.

[0120] With core cooling pull-up capacity exceeded control sets at alltimes following initial set, and plateaued at 14 pull-ups for most ofthe trial.

[0121] Thus, the challenge of this workout routine was 17% greater withcore cooling.

[0122] The results are graphically illustrated in FIG. 5.

[0123] G. Core cooling during conditioning enhances strength increases

[0124] During prior 6 weeks subject did routine 2 to 3 times per weekwith one or two core coolings on experimental days. Over that time healmost doubled his capacity from about 100 to less than 200.

[0125] During the 6 weeks shown in this figure, the subject didconditioning routine 2 to 3 times per week with repeated core cooling inevery other trial. His capacity increased more than 3 fold, from lessthan 200 to more than 600.

[0126] Gains were seen only during cooling days, but increases instrength carried over to control days.

[0127] The results are graphically illustrated in FIG. 6.

[0128] II. Additional Pull-Up Experiment

[0129] A. Basic Procedure

[0130] 14 sets of pull-ups with a 3.5 min. rest period between sets.Workouts were 2-3 days/week for 5 control weeks and 5 weeks withcooling.

[0131] B. Results

[0132] Complete results from 5 subjects have been obtained. The resultsconfirm the initial observation seen in Example I above. In 4 out of 5subjects repeated cooling between sets of aerobic exercise increased theworkout capacity. It is likely that in the non-responsive subject thecooling load applied to the heat exchange surfaces induced a localvasoconstriction that blocked the transfer of the thermal load to thebody core.

[0133] Example III. Cooling during Circuit Weight Training

[0134] A. Procedure

[0135] Subjects: 20 members of the Stanford University varsity footballteam, 12 experimental subjects, 8 controls. Basic procedure: NCAA rulesgovern the timing and duration of strength and conditioning programs forintercollegate athletes. Therefore these training sessions are carefullyregimented and monitored to maximize the benefits of the training duringthese sanctioned training sessions. For each day of training theindividual athletes are assigned a personalized workout routine thatspecifies the sequence of exercises to be performed, the targetperformance at each exercise station, and the rest interval between theexercise stations. During the summer and winter strength andconditioning programs the experimental subjects were cooled during therest intervals between exercise stations. In these studies, the durationof exposure to the cooling device was either 45 seconds or 1.5 min. Thepercent of times the subjects achieved their daily performance targetsserved as an index for assessing relative changes in fitness levels.Efficacy of the treatment was determined by differences between controland experimental conditions in the % of times that the subjects achievedtheir targeted performance levels.

[0136] B. Results

[0137] Under control conditions, subjects reached their targetperformance goals 30-50% of the time. Eight of 12 experimental subjectsachieved their target performance goals 70-80% of the time. Performanceby the remaining 4 experimental subjects was indistinguishable from thecontrol group. Factors that could have effected whether an individualresponded to treatment include; the temperature at the skin surface (iftoo cold a local vasoconstrictive response will be elicited) and theduration of treatment (45 sec treatments may be insufficient toappreciably effect the thermal condition of the body core of certainsubjects).

[0138] Example IV. Temperature Manipulations During Exercise in a HotEnvironment (33-34 Degrees C., 27-90% Relative Humidity)

[0139] A. Procedure

[0140] In this study, anaerobic exercise in a hot environment is used asa means of increasing internal boy temperature. Esophageal and tympanicmembrane temperatures and heart rate are continuously measured. Waterloss is determined by weight loss during exercise. Basic protocol; ridea stationary bicycle at a fixed load for 60 min or to exhaustion.Manipulations: control (no cooling), cooling during exercise, or coolingduring recovery from exercise.

[0141] B. Results

[0142] Four individuals were studied. Cooling during exercise reduceswater loss (20-30%), peak heart rate (10-15%), and rate of coretemperature rise (25-35%). The bottom line result is that cooling in anextreme hot environment allows an individual to sustain a given workload for a longer period of time. Cooling subsequent to exercise speedsrecovery as determined by rate of heart rate and core temperaturedeclines.

[0143] It is evident from the above results and discussion that thesubject invention provides a convenient method for extracting thermalenergy or heat from the core body of a subject. Benefits of the subjectinvention include the non-invasive, simple to perform nature of thesubject methods which provide for better patient compliance. Additionalbenefits include the non-pharmacological basis of the methods.

[0144] It is also evident from the above results and discussion that thesubject invention provides a convenient method for significantlyimproving the ability of a mammal to perform a physical task. Benefitsof this embodiment of the subject invention include the non-invasive,simple to perform nature of the subject methods. Additional benefitsinclude the non-pharmacological basis of the methods. In view of theabove discussion and results, it is readily apparent that the subjectinvention represents a significant contribution to the art.

[0145] All publications and patent applications cited in thisspecification are herein incorporated by reference as if each individualpublication or patent application were specifically and individuallyindicated to be incorporated by reference. The citation of anypublication is for its disclosure prior to the filing date and shouldnot be construed as an admission that the present invention is notentitled to antedate such publication by virtue of prior invention.

[0146] Although the foregoing invention has been described in somedetail by way of illustration and example for purposes of clarity ofunderstanding, it is readily apparent to those of ordinary skill in theart in light of the teachings of this invention that certain changes andmodifications may be made thereto without departing from the spirit orscope of the appended claims.

What is claimed is:
 1. A method for extracting thermal energy from thecore body of a mammal, said method comprising: (a) enclosing a portionof said mammal in a scaled enclosure to produce an enclosed portion ofsaid mammal; (b) contacting a surface of said enclosed portion with alow temperature medium under negative pressure conditions for a periodof time sufficient to extract thermal energy from the core body of saidmammal, wherein said low temperature medium has a temperature below saidmammal's normal physiologic temperature but above a temperature thatresults in localized vasoconstriction at said surface.
 2. The methodaccording to claim 1, wherein said portion of said mammal is a limb or aportion thereof.
 3. The method according to claim 2, wherein said limbis selected from the group consisting of an arm and a leg.
 4. The methodaccording to claim 3, wherein said portion is a heat exchange surface.5. The method according to claim 4, wherein said heat exchange surfaceis selected from the group consisting of a sole and a palm.
 6. Themethod according to claim 2, wherein said sealed enclosure under saidnegative pressure conditions has a pressure ranging from about −20 toabout −80 mm Hg.
 7. The method according to claim 2, wherein said lowtemperature medium has a temperature ranging from about 15 to about 35°C.
 8. The method according to claim 2, wherein said period of timeranges from about 0.5 min to about 24 hrs.
 9. The method according toclaim 1, wherein said mammal is a human.
 10. A method for enhancing theability of a mammal to perform a physical procedure, said methodcomprising: (a) enclosing a portion of said mammal in a sealed enclosureto produce an enclosed portion of said mammal; (b) contacting a surfaceof said enclosed portion with a low temperature medium under negativepressure conditions at least once during said physical procedure for aperiod of time sufficient to enhance the ability of said mammal toperform said physical procedure, wherein said low temperature medium hasa temperature below said mammal's normal physiologic temperature butabove a temperature that results in localized vasoconstriction at saidsurface.
 11. The method according to claim 10, wherein said portion ofsaid mammal is a limb or a portion thereof.
 12. The method according toclaim 11, wherein said limb is selected from the group consisting of anarm and a leg.
 13. The method according to claim 11, wherein saidportion is a heat exchange surface.
 14. The method according to claim13, wherein said heat exchange surface is a palm or a sole.
 15. Themethod according to claim 10, wherein said sealed enclosure under saidnegative pressure conditions has a pressure ranging from about −20 toabout −80 mm Hg.
 16. The method according to claim 10, wherein said lowtemperature medium has a temperature ranging from about 15 to about 35°C.
 17. The method according to claim 10, wherein said period of timeranges from about 0.5 to about 600 min.
 18. The method according toclaim 10, wherein said mammal is a human.
 19. The method according toclaim 10, wherein said physical procedure is an athletic procedure. 20.The method according to claim 10, wherein thermal energy is extracted toeffect rapid recovery from a heated condition.
 21. The method accordingto claim 20, wherein said heated condition occurs in a hot environment.22. The method according to claim 21, wherein said mammal is an athlete.23. The method according to claim 22, wherein said physical procedure isa sporting event or practice session.
 24. A method for enhancing theability of a mammal to perform an athletic procedure, said methodcomprising: extracting thermal energy from the body core of said mammalat least once during said athletic procedure for a period of timesufficient to enhance the ability of said mammal to perform saidathletic procedure, wherein said core body thermal energy is extractedby the method comprising: (a) enclosing a portion of said mammal in asealed enclosure to produce an enclosed portion of said mammal; (b)contacting a surface of said enclosed portion with a low temperaturemedium under negative pressure conditions for a period of timesufficient to extract said core body thermal energy, wherein said lowtemperature medium has a temperature below said mammal's normalphysiologic temperature but above a temperature that results inlocalized vasoconstriction at said surface.
 25. A device for extractingthermal energy from the core body of a mammal, said device comprising:(a) a sealable enclosure having dimensions sufficient to produce anenclosed portion of a mammal; (b) a negative pressure producing elementthat produces negative pressure conditions in said sealable enclosure;and (c) a cooling element for producing a reduced temperature medium insaid sealable enclosure; (d) wherein said devices is adapted to avoidlocalized vasoconstriction on the surface of an enclosed portion of amammal.
 26. A device for extracting thermal energy from the core body ofa mammal, said device comprising: (a) a sealable enclosure havingdimensions sufficient to produce an enclosed portion of a mammal; (b) anegative pressure producing element that produces negative pressureconditions in said sealable enclosure; and (c) a cooling element forproducing a reduced temperature medium in said sealable enclosure,wherein said reduced temperature medium is at a temperature to avoidlocalized vasoconstriction on the surface of an enclosed portion of amammal.
 27. A device for enhancing the ability of a mammal to perform aphysical procedure, said device comprising: (a) a sealable enclosurehaving dimensions sufficient to produce an enclosed portion of a mammal;(b) a negative pressure producing element that produces negativepressure conditions in said sealable enclosure; and (c) a coolingelement for producing a reduced temperature medium in said sealableenclosure; (d) wherein said devices is adapted to avoid localizedvasoconstriction on the surface of an enclosed portion of a mammal. 28.A device for enhancing the ability of a mammal to perform a physicalprocedure, said device comprising: (a) a sealable enclosure havingdimensions sufficient to produce an enclosed portion of a mammal; (b) anegative pressure producing element that produces negative pressureconditions in said sealable enclosure; and (c) a cooling element forproducing a reduced temperature medium in said sealable enclosure,wherein said reduced temperature medium is at a temperature to avoidlocalized vasoconstriction on the surface of an enclosed portion of amammal.